Electric-furnace apparatus and process of revivifying decolorizing carbon, etc.



Juil 5, 1921. 1934,47

L. WICKENDEN ET AL ELECTRIC FURNACE APPARATUS AND PROCESS OF REVIVIFYING DECOLORIZING CARBON, ETC- Filed July 3, 1922 JNVENTORS Patented July 5, 1927.

sra'rs LEONARD WICKENIDEN, 0F FLUSHING, AN

D WALTER F. DEMMERLE, OF NEW YORK,

N. Y., ASSIGNORS 'LO INDUSTRIAL CHEMICAL COMPANY, OF NEW YORK, N. Y., A.

CORPORATION 01 NEW YORK.

ELECTRIC-FURNACE APPABATUS AND 'PROCESS OF REVIVI FYING DECOLORIZING CARBON, ETC.

Application filed July 3,

water solutions the filter cake may sometimes contain upwards of 70% moisture and may, in many cases, be advantageously dried to remove at least a considerable part of this water and then fed into an electric furnace in which a number of depending or otherwise projecting members or rods, which may act either as heating elements or electrodes or stirrers, are arranged so as to engage this mass or carbon and agitate the same through the relative rotation or other movement of the rods with respect to the furnace which may, in some cases, form or comprise one of the electrodes. These electrodes, which may be in the form of rods or blocks of cast iron, resistant iron alloys graphitic carbon, or any suitable conducting material possessing av high melting point, may depend from the support or cover into the relatively rotating furnace or substantially closed heating chamber and may be so arranged within the furnace as to engage and agitatethe mass of carbon. At the same time, the temperature of the carbon is raised as by the passage of an electric current through it from one electrode; to-another so that any remaining water is driven off and the carbon substantially uniformly heated to the desired revivifying temperature of 400 to 700 0.,

more or less, according to the natureof the carbon and the treatment desired, and when its treatment is complete, in the course of activating of the carbon, it may be substantially completely discharged from the furnace.

In the accompanying drawing showing in a somewhat diagrammatic way various illustrative embodiments of the invention Fig. 1 is a vertical section through a rotating furnace,

1922. Serial No. 572,384.

be composed of some refractory material of relatively high electrical conductivity such as carborundum or other suitable material; or if the furnace is not to act as an electrode, this lining may be composed of a refractory material such as fire brick or clay, or other suitable material. Either of these elements may rotate with respect to the other and the furnace may as indicated, be provided with a series of supporting rolls or flanged. bearing wheels 18, engaging a. circular track 19 so that the furnace may be rotated as by the crown gear 4: on the furnace shell and the cooperating driving pinion 5. In this way the furnace may be rotated at the desired speed during the process, a few revolutions aminute usually being suflicient with a three or four foot furnace to give the desired agitating and effects. Thefurnace bottom may be provided with a hinged discharge door 20 which may be opened and closed by any suitable mechanism, which will enable the door to be opened gradually to any degree, thus making possible the regulated discharge ofthe furnace contents.

The cover 1 preferably has a depending vcover flange 7 fitting fairly closely into the furnace top and on which may be supported one or more scrapers or stirrer-s 8, secured thereto as by the bolts 9, so as to project into the furnace adjacent its walls and agitate this part of the material and also detach adherent masses from the walls. A feed chute such as 10, preferably having a nor- -mally closed upper end may'also advantageously be provided in the cover so as to allow the material to be fed into the furnace in any desired manner, substantially continuously if desired, from any suitable preheating or drying devices which may be used such as the substantially enclosed drier distributed heating which the material may be slowly siderable evolution of volatile matter from the organic matter held in the pores of the carbon; and air is, in some cases, permitted to enter the upper part of the furnace in sufiicient amount to cause this volatile matter to burn, so that the total amount of heat evolved from he furnace and available for pre-drying is considerable. This drier 34 also serves to collect any carbon particles which are carried out of the furnace so that dusting losses are minimized.

Electrodes of any suitable character may also be supported on the cover and may be fitted with insulatin bushings or sugports 11 screwed into or tiherwise secured t ereto so as to form a sufliciently firm insulating support for the electrodes such as 14, 15

and 16, of which any desired number may be used in each of the groups or rows whch may extend across the furnace or be othertating an wise grou ed so as to give the greatest agidistribute'd heating effect. These electrodes may be used to convey or conduct the electric current to the mass of carbon in the furnace where (due either to the resistance of the carbon to the passage of the electric current or to theminute electric. arcs formed between the electrodes and the particles of carbon, or between the particles of carbon themselves, or to any or all of these actions) heat is generated in sufficient amounts to drive off any water or other volatile matter contained in the carbon and raise the carbon to the desired revivifying temperature. Suitable connector clamps such as 12 may be secured to these electrodes to hold them at the desired height and to conduct the electricity thereto as through the wires 22, 23 and 24, which may be connected .up

as indicated in Fig. 2 where a direct current or single phase alternating current supply is employed. This staggered arrangement of the electrodes indicated in Fig. 2 gives a substantially uniform s acing between each of the adjacent electro' es connected to o posite sides 'of the supply system, so that t e currents passing and the resulting heating effects are relatively constant; and of course these electrodes by their relative rotation with respect to the furnace not only uniformly agitate the material in the furnace but constantly change the ath of current through the carbon, so t at during the process of drying and heating the heat is generated substantially uniformly throughout the entire mass of the furnace contents.

Fig. 3 shows another arrangement of elecfrom each other which is of rema n g er employed and the fineness and quality of.

the material treated, etc. Fig. 4 shows an other arrangement of electrodes particularly adapted for a three-phase alternating current supily, the different electrodes being connecte as by the wires or leads 31 with the supply wires 28, 29 and 30 so that the adjacent cooperating electrodes of different phase are arranged at a distance d apart 4 course selected so as to give the desired operating and heat ing effects and to balance the electrical load between the three phases of the system. If it is desired to utilize a three-phase, a fourwire system, the same general arrangement and spacing can-be used as is shown in Fig. 4, except that the neutral wire of the system may be connected to the earth. A two-phase, four-wire system can be utilized by connecting one phase to each of two separate and distinct furnaces; and the connections and arrangements of the electrodes in each furnace could be substantially those of a single phase or direct current system as shown in Fig. 2. A direct current, three-wire or socalled Edison system can be utilized by arranging the spacing substantially as shown in Fig. 2 for a single phase or direct current system, the two outside wires being connected as to 22, 24 while the neutral or middle wire may be connected to the earth.

Under certain conditions the cakes of finely divided or powdered carbon from the filter presses, preferably after being more or less broken up, may be fed into the pre-drier toany desired extent. The percentage of mois-'- ture in this carbon may then be appreciably reduced in the preliminary drier as by means of the drying effect of the steam and hot gases produced in the furnace during the heat treatment of the previous charge. When the furnace has been em tied of this charge the heated carbon in t e dryer for instance is fed into the furnace which is filled to any desired level such as is indicated in Fig. 1. The furnace is then rotated so that the charge of carbon is continually carried into contact with andbetween the electrodes 14, 15 and 16 so that the carbon is agitated and, at the same time, heat is generated in the material due to the passage of the electric current through it, or to elec trio arcs occuring as previously noted. Any contalned in the carbon is thus driven off and the carbon itselfis heated up to the desired revivifying or activatmg temperature of 400 to 700 Q. more or less. Owing to the fact that the carbon is kept in a state of continual agitation and is forced by the movement of the furnace to travel between the electrodes, any lumps of carbon are broken up very thoroughly and by the time the revivifying action is complete, the carbon is ready to be delivered from the furnace in a finely powdered condition. Moreover, owing to the fact that the heat is generated within the carbon itself, and as every particle of carbon in the furnace is frequently caused to pass between the electrodes, a far more thorough and uniform heating of the mass can be obtained than in the usual revivifying furnaces in.

which the heating is by conduction from external sources of heat. When the original properties of the carbon have been restored by the treatment described above, thecarbon may be discharged from the furnace by opening the door 20 in such a manner that the carbon can be discharged in a steady and well controlled stream preferably into a closed chute 33 below, leading to a water tank or other receptacle substantially free from air so as to prevent oxidation losses. When the carbon has been used for the treatment of oils, .fats,'waxes, organic liquids and other similar materials, it is obviousthat predrying will be unnecessary, and in such cases the carbon may be fed-directly into the revivifier from the filter-presses or it may be limited since ,what is claimed as new first extracted with benzol, naphtha, carbontetrachloride or any suitable solvent and then,. being substantially free from the material on which it has been used, it can be fed to the furnace and subjected to electrical heat treatment in the manner described.

This invention has been'disclosed in connection with a number of illustrative forms, of apparatus, terials, methods of operation, conditions and temperatures, to the details of which disclosure the invention is not of course to the Y Letters Patent is set forth in the appended claims.

We claim- 1. The rotary electric furnace for revivifying decolorizing carbonfetc. comprising a substantially vertical cylindrical furnacehaving a refractory lining and mounted to be rotated about its axis, cooperating rotating means, a discharge door adjacent the center of the furnace bottom, a cover cooperating wth said furnace and having a depending flange fitting substantially closely the upper end of the furnace, a scraper mounted on said cover to cooperate with the side of the furnace, a feed chute in said cover and three transverse rows of depending 'agitat ing and heating electrodes extending into devices, parts, propprtions, ma-

said furnace adjacent the bottom thereof and insulating supports between said electrodes and the furnace cover.

2'. Therotary electric furnace for revivifying decolorizing carbon, etc. comprising a substantially vertical furnace having a refractory lining and mounted to be rotated, cooperating rotating means, a discharge door adjacent the furnace bottom, a cover cooperating with said furnace and fitting substantially closely the upper end of the furnace, a scraper mounted on said cover to cooperate with the side of the furnace, a feed chute in said cover and depending agitating and heating electrodes extending into said furnace adjacent the bottom thereof and insulating supports between said electrodes and the furnace cover.

3/ The electric furnace for revivifying decolorizing carbon, etc. comprising a substantially Vertical furnace having a refractory linlng, a relatively rotating cover cooperating withsaid furnace, a series of depending agitating and heating electrodes maintained 'at different potentials and mounted on said cover and extending into said furnace adjacent the bottom thereof hill and electric connections for saidelectrodes 5. The rotary electric furnace adapted for revivifying or activating 'decolorizing carbon, etc. comprising a furnace and cooperating cover, means to effect the relative rotation of said furnace and cover, means adapted to feed finely divided decolorizing carbon into and out of said furnace without undesirable oxidizing contact with the air and a series of heating electrodes extending into said furnace adjacent an inner surface thereof to engage the relatively moving carbonaceous charge and agitate and heat the same b the heating currents supplied to said cli arge by said electrodes.

6. The rotary electric furnace adapted for revivifying or activating decolorizing 'carbon, etc. comprising a furnace and cooperating support, means to effect the relative rotation of said furnace and support, and a series of heating electrodes extending into said furnace adjacent an inner surface there-. of to engage therelatively moving carbonaceous charge and agitate and heat the same by the heating currents supplied to said charge by said electrodes.

7. The electric furnace adapted for revivifying or activating decolorizing carbon, etc. comprising a furnace, means adapted to allow the feed of decolorizing carbon into. and out of said furnace, a series of heating electrodes extending into said furnace adjacent an inner surface thereof to engage the carbonaceous furnace charge, and'means to efi'ectrelative movement between said electrodes and said charge to agitate and heat the same by the heating currents passing through said charge from said electrodes.

8. The electricfurnace process of revivifying powdered decolorizing carbon which comprises at least partly drying the moist decolorizing carbon and feeding the same into a rotating electric furnace and thereby carrying the same into contact with a series of heating electrodes at different potentials to agitate'and heat the carbon to the desired revivifying temperatures without objectionable air currents and discharging the revivified carbon from the furnace while preventing undesirable oxidation thereof.

9. The electric furnace process of revivifying powdered decolorizing carbon, which comprises feeding the decolorizing carbon into a rotating electric furnace and thereby carrying the same into contact with a series of heating electrodes at different potentials to agitate and heat the carbon to the desired revivifying temperatures without objectionable air currents.

10. The electric furnace process of revivifying powdered or finely divided decolorizing carbon, etc. which comprises continuously moving the decolorizing carbon to carry the same into contact with a series of electric heating elements to agitate and heat the carbon to the desired revivifying temperatures without objectionable air currents,

11. The electric furnace process of treating powdered or finely divided decolorizing carbon, etc. which comprises moving the decolorizing carbon to carry the same into contact with a series of electric heating elements to agitate and heat the carbon to the desired temperatures without objectionable air currents.

12. The electric process of revivifying powdered or finely divided decolorizing carbon, etc. which comprises continuously rotating the moist decolorizing carbon to carry the same into contact with a series of agitating heating electrodes to agitate and heat the carbon to the desired revivifying temperatures within a substantially enclosed furnace chamber without objectionable air currents and discharging the revivified carbon from the chamber while preventing undesirable oxidation thereof.

13. The process of revivifying powdered or finely divided decolorizing carbon, etc. which comprises continuously rotating the decolorizing carbon to carry the same into contact with a series of heating electrodes to agitate and heat the carbon to the desired revivifying temperatures without objectionable air currents and discharging the revivified carbon while preventing undesirable oxidation thereof.

14. The process of revivifiying powdered or finely divided decolorizing carbon, etc.

which comprises moving the decolorizing revivified carbon while preventing undesirable oxidation thereof.

16. The process of manufacturing or treating powdered or finely divided decolorizing carbon, etc. which comprises continuously moving decolorizing carbon to carry the same into contact with a heating electrode to agitate and heat the carbon to the desired temperatures without objectionable air currents.

LEONARD WICKENDEN. WALTER F. DEMMERLE. 

